S2000 AP1 Fault - Advice required

Drollic · 28 Oct 2019 at 15:40

My AP1 S2000 has seemingly developed a very random intermittent fault. Twice now over a period of probably 6-8 weeks the car has cut out whilst driving with both the engine management light and green key fob symbol flashing/flickering when it cuts out. The first time this happened the car restarted straight afterwards and was fine up until this weekend just gone. The car cut out again except this time, upon restarting it again cut out within a minute. Once cooled down and restarted it's been fine since. An AA mechanic was unable to diagnose the fault (he agreed thinking it's electrical/relay) and the car is now booked in with a Honda dealership to try and find the issue at a cost of £115 already. This doesn't include possible extra parts cost or labour.

The only other issue I've had with the car in 4 years of ownership is the key fob not being accepted to start the car - the unlock door button on the fob used to start it doesn't go out as it should and simply flashes. This is again seemingly completely random and very rarely occurs. Eventually you can start the car as per normal and the issue is gone for months. A new key fob battery has possibly fixed this although I'm unsure - it could be related.

I'm pretty sure it's not mechanical as the car drives as it should and it's fairly well looked after with a clean MOT earlier this year as well.

Any suggestions on what the issue could be and what I should be expecting to pay? I'm guessing it could be immobiliser related (a weak point I believe on AP1s) and if so, what do you recommend as it's so old they won't be able to directly replace? The other possibility is the key barrel/ignition being faulty and not recognising the key is turned I've been told? The spark plugs are less than 4 years old with well under 25k on them, no idea how old the leads are and the battery is less than 8 months old. I don't want to be at the mercy of the Honda dealership saying it's x, y and z with a huge bill if I can help it due to the value of the car itself.

Rilot · 29 Oct 2019 at 08:59

Sounds like a short or loose contact in the ignition barrell causing the car to think that the key has been removed.

Marc2180 · 29 Oct 2019 at 10:30

The alarm system fitted to the AP1's was a Hamilton & Palmer system fitted by the dealers when they were delivered as they didn't come with one from the factory. Maybe its the H&P immobiliser kicking in? battery dying on the H&P locking fob?

Drollic · 29 Oct 2019 at 11:10

Marc2180 said:
The alarm system fitted to the AP1's was a Hamilton & Palmer system fitted by the dealers when they were delivered as they didn't come with one from the factory. Maybe its the H&P immobiliser kicking in? battery dying on the H&P locking fob?

Fob battery only just replaced. Yes it's that system. Pretty sure it's the issue or as above the barrel. Just wondered if it could be something simple that's been overlooked.

lemonade · 30 Oct 2019 at 10:20

It will be a worn ignition switch, not barrel. The Accord from that era had reported issues with the car cutting out during driving and the fault is worn ignition switch. Which is a simple fix, just buy a new switch and change over.

Drollic · 30 Oct 2019 at 12:05

lemonade said:
It will be a worn ignition switch, not barrel. The Accord from that era had reported issues with the car cutting out during driving and the fault is worn ignition switch. Which is a simple fix, just buy a new switch and change over.

Direct swap, no new keys or reprogramme? Just looking that up it does seem likely. Thanks

lemonade · 30 Oct 2019 at 12:14

No need for keys as your not changing the barrel and shouldn't need to reprogram either, but don't quote me on the latter as I'm not familiar with the S2000's system. Otherwise it's a direct swap and a simple enough DIY job usually.

DXP55 · 30 Oct 2019 at 12:51

Although it's not a S2000 My Focus had a paddy while the wife was visiting her sisters. She came out to come home and it wouldn't start so called breakdown - The AA man was stumped for a while then he found two earth wires under the kick plate under drivers door - cleaned them up and it started although all the dash lights we flickering and coming on and going off.
Next day I checked as many earth wire as I could and the common denominator with all of them was captive nut's on back of metal - Ford seem to reply on the bolt alone creating the earth as these and cable loop was clamped to painted body - I cleaned off the paintwork and tightened up and all has been fine.
This may have nothing to do with your fault but it illustrates how random a fault can be.

Drollic · 30 Oct 2019 at 14:22

DXP55 said:
Although it's not a S2000 My Focus had a paddy while the wife was visiting her sisters. She came out to come home and it wouldn't start so called breakdown - The AA man was stumped for a while then he found two earth wires under the kick plate under drivers door - cleaned them up and it started although all the dash lights we flickering and coming on and going off.
Next day I checked as many earth wire as I could and the common denominator with all of them was captive nut's on back of metal - Ford seem to reply on the bolt alone creating the earth as these and cable loop was clamped to painted body - I cleaned off the paintwork and tightened up and all has been fine.
This may have nothing to do with your fault but it illustrates how random a fault can be.

There's posts on one of the US s2000 forums relating to that but it seems very unlikely. I thought if your cars electrics like lights, radio etc work, your car is earthed. Honda haven't been able to replicate the fault so they're checking this ignition switch.

jpaul · 30 Oct 2019 at 15:04

voltage regulators, maybe, but presumably you have seen no obvious correlation with the use of other electrical systems in the car.

EssexBoy · 30 Oct 2019 at 15:09

Could be crankshaft\camshaft position sensor playing up as had similar before on another car.

Drollic · 31 Oct 2019 at 00:52

jpaul said:
voltage regulators, maybe, but presumably you have seen no obvious correlation with the use of other electrical systems in the car.

Just the key not seemingly being recognised on startup, but this is pretty rare. Lights work as they should, no issue with dash lights normally etc. and battery seems fine so I'm doubting it would be that.

EssexBoy said:
Could be crankshaft\camshaft position sensor playing up as had similar before on another car.

Yes, looked this one up although I'm not sure you would get dashboard flicker from this. More likely just stall and engine management light I'd think.

Drollic · 31 Oct 2019 at 18:20

Honda have removed the ignition switch saying it's in good condition for the age of the car and are doubtful it's the issue. They don't think it's battery, alternator or grounding issue either. They can't replicate the fault and don't seem to want to help any further. They want £70 for removing and checking this switch as opposed to £114 for a diag check given they can't tell me what the issue is. Switch alone is around £120 and might/might not fix the issue. Same goes for ignition switch plus barrel at around £380 together with immobiliser at what would be a fair chunk of money with no guarantee. Not really willing to throw money at it unless I know what the problem is but no idea on how to get an answer on this.

Marc2180 · 31 Oct 2019 at 18:24

Perhaps contact Hamilton & Palmer see if it's something they might have came across as it could be an immobiliser issue?

bJN · 31 Oct 2019 at 18:33

Get on the owner forums and perhaps have a chat to reputable independent places that deal with these cars regularly; Tegiwa etc and see if they can come up with anything.

Drollic · 31 Oct 2019 at 18:42

Marc2180 said:
Perhaps contact Hamilton & Palmer see if it's something they might have came across as it could be an immobiliser issue?

bJN said:
Get on the owner forums and perhaps have a chat to reputable independent places that deal with these cars regularly; Tegiwa etc and see if they can come up with anything.

I was thinking of tdi north as well. I'll speak with h&p tomorrow morning. Presumably it's possible to disable an immobiliser temporarily in that once done, if the issue doesn't happen again, atleast you know that's the cause.

On Holiday · 31 Oct 2019 at 18:44

Drollic · 31 Oct 2019 at 20:17

The more I look online, the more the issue seems to point at the immobiliser given they think the ignition switch is ok. The recall on the accord for the ignition switch along with 8 or so other Honda models didn't include the s2000. It's either that or the infrequent startup issue with green key flashing isn't related to this random cutout problem. It can cut power to the fuel pump though as I understand it, which in turn might mean no fault code stored. These issues seem specific to the AP1 with the problematic H&P system. I don't want a new circuit board at the cost of £200 if it has the potential to go wrong again. Apparently older fuel pumps drawing more current than when new can even cause an issue with this system.

My ideal would be to disable/remove the immobiliser I think.

Marc2180 · 1 Nov 2019 at 10:46

Drollic said:
The more I look online, the more the issue seems to point at the immobiliser given they think the ignition switch is ok. The recall on the accord for the ignition switch along with 8 or so other Honda models didn't include the s2000. It's either that or the infrequent startup issue with green key flashing isn't related to this random cutout problem. It can cut power to the fuel pump though as I understand it, which in turn might mean no fault code stored. These issues seem specific to the AP1 with the problematic H&P system. I don't want a new circuit board at the cost of £200 if it has the potential to go wrong again. Apparently older fuel pumps drawing more current than when new can even cause an issue with this system.

My ideal would be to disable/remove the immobiliser I think.

A good auto electrician should be able to remove the immobiliser. I would replace it with another alarm/immobiliser system though.

Drollic · 1 Nov 2019 at 13:40

Marc2180 said:
A good auto electrician should be able to remove the immobiliser. I would replace it with another alarm/immobiliser system though.

A local auto electrician is coming to look at it tomorrow. Mentioned he's seen the green key start issue on another older Honda although not an S2000. I spoke to H&P this morning and some of the reported faults online including the fuel pump burnt out wiring connection on the circuit board itself are apparently down to Honda changing specs at the last minute so they couldn't do the r&d that they would have liked before fitment. Regardless of that it's now 19 years old.

Whatever is cutting the engine must also be cutting the power so the ecu can't record the fault I'd think.